This invention relates to a heat exchanger for use in a reversible vapor compression system and, in particular, to a heat exchanger that is capable of effectively performing as either a condenser or an evaporator in a heat pump environment.
Generally, in the reversible refrigeration system a pair of heat exchangers, typically being an indoor heat exchanger and an outdoor heat exchanger, are selectively connected to a compressor by means of a four-way valve or the like. By selectively positioning the valve, the discharge from the compressor is routed to one or the other of the exchangers to deliver either heating or cooling to the indoor region. When cooling is to be provided, the outdoor exchanger is called upon to serve as a condenser in the system while the indoor coil must perform as an evaporator. Switching to a heating mode of operation reverses the roles of the two exchangers.
It is well known in the art that a heat exchanger that is specifically designed to function as a condenser does not under ordinary circumstances function as well when required to serve as an evaporator. As a consequence, heat exchangers normally employed in most heat pumps represent a compromise in design which places an adverse limitation on the overall performance of the system.